Effects of heat stress on virus transmission and virus-mediated apoptosis in whitefly Bemisia tabaci

Tomato yellow leaf curl virus: Characteristics, influence, and regulation mechanism

Tomato yellow leaf curl virus (TYLCV), a DNA virus belonging to the genus Begomovirus, significantly impedes the growth and development of numerous host plants, including tomatoes and peppers. Due to its rapid mutation rate and frequent recombination events, achieving complete control of TYLCV proves exceptionally challenging. Consequently, identifying resistance mechanisms become crucial for safeguarding host plants from TYLCV-induced damage. This review article delves into the global distribution, dispersal patterns, and defining characteristics of TYLCV. Moreover, the intricate interplay between TYLCV and various influencing factors, such as insect vectors, susceptible host plants, and abiotic stresses, plays a pivotal role in plant-TYLCV interactions. The review offers an updated perspective on recent investigations focused on plant response mechanisms to TYLCV infection, including the intricate relationship between TYLCV, whiteflies, and regulatory factors. This comprehensive analysis aims to establish a foundation for future research endeavors exploring the molecular mechanisms underlying TYLCV infection and the development of plant resistance through breeding programs.

VDAC1 balances mitophagy and apoptosis in leafhopper upon arbovirus infection

Mitophagy is a form of autophagy that selectively removes damaged mitochondria and attenuates mitochondrial-dependent apoptosis during viral infection, but how arboviruses balance mitophagy and apoptosis to facilitate persistent viral infection in insect vectors without causing evident fitness cost remains elusive. Here, we identified mitochondrial VDAC1 (voltage-dependent anion channel 1) that could be hijacked by nonstructural protein Pns11 of rice gall dwarf virus (RGDV), a plant nonenveloped double-stranded RNA virus, to synergistically activate pro-viral extensive mitophagy and limited apoptosis in leafhopper vectors. The direct target of fibrillar structures constructed by Pns11 with VDAC1 induced mitochondrial degeneration. Moreover, the degenerated mitochondria were recruited into Pns11-induced phagophores to initiate mitophagy via interaction of VDAC1 with Pns11 and an autophagy protein, ATG8. Such mitophagy mediated by Pns11 and VDAC1 required the classical PRKN/Parkin-PINK1 pathway. VDAC1 regulates apoptosis by controlling the release of apoptotic signaling molecules through its pore, while the anti-apoptotic protein GSN (gelsolin) could bind to VDAC1 pore. We demonstrated that the interaction of Pns11 with VDAC1 and gelsolin decreased VDAC1 expression but increased GSN expression, which prevented the extensive apoptotic response in virus-infected regions. Meanwhile, virus-induced mitophagy also effectively prevented extensive apoptotic response to decrease apoptosis-caused insect fitness cost. The subsequent fusion of virus-loaded mitophagosomes with lysosomes is prevented, and thus such mitophagosomes are exploited for persistent spread of virions within insect bodies. Our results reveal a new strategy for arboviruses to balance and exploit mitophagy and apoptosis, resulting in an optimal intracellular environment for persistent viral propagation in insect vectors.Abbreviations: ATG: autophagy related; BNIP3: BCL2 interacting protein 3; CYCS/CytC: cytochrome c, somatic; dsGSN: double-stranded RNAs targeting GSN/gelsolin; dsGFP: double-stranded RNAs targeting green fluorescent protein; dsPRKN: double-stranded RNAs targeting PRKN; dsPns11: double-stranded RNAs targeting Pns11; dsRNA: double-stranded RNA; EC: epithelia cell; GST: glutathione S-transferase; LAMP1: lysosomal associated membrane protein 1; Mito: mitochondrion; Mmg: middle midgut; MP, mitophagosome; PG, phagophore. padp: post-first access to diseased plants; PINK1: PTEN induced kinase 1; RGDV: rice gall dwarf virus; SQSTM1: sequestosome 1; TOMM20: translocase of outer mitochondrial membrane 20; TUNEL: terminal deoxynucleotidyl transferase dUTP nick end labeling; VDAC1: voltage dependent anion channel 1.